It doesn’t seem like that long ago when Netscape Navigator was my browser of choice and I thought you couldn’t get any better than a resolution of 1024×768. Google Chrome is now my preferred Web Browser and 1680×1050 is my current resolution. It will be interesting to see what we are using 10 or 20 years from now.

I hate being negative, but this is a terrible way to use pie charts and your methodologies are questionable. Reading dates backwards is very unintuitive for one thing. Not only are these graphs hard to follow, but the numbers are completely fucking wrong for a few. Like the Netscape percentages. Did you not bother to check those before publishing this?
There are a zillion ways you could show this data and I hate to say it, but you pretty much choose the more horrible of the bunch.

Stats based on w3schools are not a good base for this case study as the 'users' will be web designers, developers and students so will not paint an accurate picture of web users as a whole.
I quote from the site "W3Schools is a website for people with an interest for web technologies. These people are more interested in using alternative browsers than the average user. The average user tends to use Internet Explorer, since it comes preinstalled with Windows. Most do not seek out other browsers.
These facts indicate that the browser figures above are not 100% realistic. Other web sites have statistics showing that Internet Explorer is used by at least 80% of the users." - source: http://w3schools.com/browsers/browsers_stats.asp

I don't believe so. It's a trend of the users you sampled (in this case, mostly designers/devs). Effectively, you've looked at a user base thats already swayed in one direction. Designers and developers usually keep on top of tech. So the majority of them would have the better/larger screens, using the best browsers of the time period. To get a more accurate result, you would have to pull data from a more neutral website, Google for example. Google is used by both nerds and average users alike, so their user stats shouldn't have a predisposition towards any group.